1. Technical Field
The present invention relates to an optical crystal and to a terahertz wave generation device and method.
2. Related Art
Heretofore, non-linear optical crystals have been known that are capable of generating terahertz waves using a difference-frequency generation effect, namely a non-linear optical effect. Characteristics of the terahertz waves that are generated are dependent on the physical characteristics of the non-linear optical crystals that are used. Therefore, the frequency ranges of the terahertz waves generated by the non-linear optical crystals that are used have particular characteristics of those crystals. Accordingly, obtaining terahertz waves with desired output characteristics in accordance with purposes of use of the terahertz waves is desired.
An organic material for generating terahertz waves has been proposed (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2007-328145) in which non-linear optical crystals that are used for generating terahertz waves are formed into a mixed crystal containing a component A and a component B, as a result of which a fall in the intensity of the generated terahertz waves in a characteristic frequency region is suppressed.
However, although a fall in the intensity of the generated terahertz waves in a characteristic frequency region is suppressed to some extent by using the organic material for generating terahertz waves recited in JP-A No. 2007-328145, in the resulting characteristic, the intensity does fall in both a frequency region in which the intensity of terahertz waves generated using a non-linear optical crystal of component A alone would fall and a frequency region in which the intensity of terahertz waves generated using a non-linear optical crystal of component B alone would fall.